#!/bin/bash

# define function
current_time() {
	date '+%Y-%m-%d %H:%M:%S'
}

my_sum() {
	echo
	echo "first param : $1"
	echo "second param : $2"
	return $(($1 + $2))
}

# call function
echo "current time is : $(current_time)"
echo
my_sum 10 20
echo "10 + 20 = $?"
